How can you implement forkJoin for multiple API responses aggregation

Question

Can i know How can you implement forkJoin for multiple API responses aggregation?

Answer 1

In Angular, forkJoin is used to combine multiple HTTP requests and return the responses only when all requests are completed. It is useful when:

You need to make multiple API calls in parallel.

You need to aggregate the responses after all requests finish.

You don’t need intermediate results (as forkJoin waits for all observables to complete).

Implementation of forkJoin for multiple API responses

import { forkJoin } from 'rxjs';

import { HttpClient } from '@angular/common/http';

constructor(private http: HttpClient) {}

fetchData() {

  const userDetails$ = this.http.get('https://api.example.com/user/1');

  const userPosts$ = this.http.get('https://api.example.com/user/1/posts');

  const userComments$ = this.http.get('https://api.example.com/user/1/comments');

  forkJoin({

    user: userDetails$,

    posts: userPosts$,

    comments: userComments$

  }).subscribe(results => {

    console.log('User:', results.user);

    console.log('Posts:', results.posts);

    console.log('Comments:', results.comments);

  });

}